1. Field of the Invention
The present invention relates to overvoltage surge arrestor assemblies for protecting telephone communication lines from overvoltage occurring thereon, and more particularly, to enhance surge voltage arrestor assemblies having back-up surge features in order to protect the communication lines.
2. Discussion of the Relevant Art
The most pertinent patent appears to be that to Huvet, U.S. Pat. No. 4,502,087, issued Feb. 26, 1985, which discloses a surge voltage assembly that includes a threaded tubular housing member coupled to a circuit ground and includes therein an axially aligned compression spring, metallic cage with extending resilient fingers, a solder pellet and a gas-filled tube having a primary arc gap and an insulator with secondary arc gap holes separating a pair of electrically conductive members which contacts one terminal of the gas-filled tube and a metallic cage to hold these items. A two terminal gas tube is used herein and thus it would require two of these assemblies to provide the same function as the instant invention and an entirely different mechanical construction.
The patent to Pagliuca, U.S. Pat. No. 4,150,414, issued Apr. 17, 1979, discloses a short circuit clip with legs for resiliently engaging a line and ground electrode of a gas tube arrestor and includes an air gap device at one set of legs. The device also uses a non-metallic fusible element interposed between the clip legs and associate arrestor electrode.
The patent to Masghati, et al, U.S. Pat. No. 5,029,302, issued on Jul. 2, 1991, discloses a fail-safe arrestor for electrical circuits that uses a gas filled tube to conduct an over-voltage and provides a clip to couple the circuit to a ground lead at the melting from continuous current flow of an insulator interposed between an electrode and the ground lead. The insulator is a mesh with a plurality of passages allowing arcing between the electrode and clip at or above a predetermined voltage, thus the ground lead is supplied for a vented gas-filled tube. A pair of these units would be required to accomplish protection for both the ring and tip circuits connected to telephone communication lines and a different mechanical arrangement.
The patent to Baumbach, U.S. Pat. No. 4,314,304, issued on Feb. 2, 1982, discloses a gas-tube surge arrestor and utilizes a secondary or back-up protector should the gas tube fail. The secondary air gap is established by perforated plastic sheets which are interposed between a line terminal and a ground contact both of which are supported on an insulated base. The means for holding the gas tube and the back-up overvoltage protection device require a plurality of brackets which is different than that shown in the instant invention.
The instant invention overcomes the shortcomings found in the prior art by providing an assembly which is suitable for use with a gas-filled tube or a solid state semiconductor overvoltage protection device having a configuration similar to the tube.